Method of packaging meat



1963 c. E. PALMER METHOD OF PACKAGING MEAT Filed March 2,5, 1959 FIG. 2

' INVENTOR. CHAEL 5 E. PALMER ATTO NEYS United States Patent 3,074,798METHOD OF PACKAGING MEAT Charles E. Palmer, Turnpike Road, Somers, Conn.Filed Mar. 25, 1959, Ser. No. 801,839 4 Claims. ((21. 99-174 Thisinvention relates to plastic packages, and more particularly to a novelplastic tray for packaging meats, poultry, fish, and the like.

In the packaging industry, the use of plastic containers has becomewide-spread because of the appeal which transparent enclosures have tothe consumer. Such packages enable the shopper to inspect the product,and oftentimes a pleasingly displayed item will engender a desire topurchase.

Conventional plastic packaging films alone have not been suitable in themeat packaging industry because a substantially rigid base or tray forthe package is generally necessary. Thus, the meat packages employed inself-service stores usually consist of a cardboard or fiber tray uponwhich the meat is placed, and a heat-sealable plastic film encirclesboth tray and meat. Such packages have been objectionable in that thefiber tray absorbs the meat juices and becomes both soggy and unsightly.Additionally, the cardboard or fiber trays do not permit inspection ofthe bottom of the packaged article.

The term meat, as used herein, refers to meat, poultry, fish, and thelike.

It has heretofore been proposed to form the tray from a rigid orsemi-rigid plastic sheet to overcome the foregoing disadvantages.However, meat stored in such trays surprisingly has turned grey or brownwithin a short period of time, thus reducing greatly the value of suchan enclosure.

It is an object of the present invention to provide a novel tray formeat packaging.

It is a specific object to provide a transparent plastic tray for meatpackaging which substantially prevents discoloration of meats receivedtherein.

A further object is to provide a blank for a transparent meat packagingtray which may be printed or otherwise decorated, and which is easilyassembled.

Other objects and advantages will be readily apparent from the followingdetailed description and attached drawing wherein:

FIG. 1 is a perspective view of a meat package having a tray for-medfrom a blank prepared in accordance with this invention;

FIG. 2 is a plan view of a blank embodying the present invention;

FIG. 3 is a section along the line 3-3 of FIG. 2; and

FIG. 4 is a perspective view of a tray formed from the blank of FIG. 2with one corner unassembled.

it has been found that a semi-rigid plastic tray which substantiallyprevents meat discoloration can be made from a blank consisting of asemi-rigid plastic sheet having a multiplicity of spaced perforationsand placed in an envelope of flexible plastic film, i.e., interposedbetween two sheets of the film.

Although the nature of the beneficial effect accomplished by thecombination of the perforated semi-rigid sheet and envelope of flexibleplastic film is not fully understood, it is surmised that the heavyplastic sheet stock necessary to provide a semi-rigid tray is notpermeable to gases, especially oxygen, and that this is the cause of thediscoloration of the meats. In the present invention, the perforatedstructure of the semi-rigid sheet in cooperation with the envelope ofrelatively gas-permeable resilient film may provide both a reservoir ofoxygen and a. gas-permeable structure at the perforations. It is "ice tobe understood, however, that the invention is not to be limited to theforegoing theory of operation.

Referring to the attached drawing, the blank of the present invention iscomprised of a semi-rigid plastic sheet 2 encased in an envelope of twosheets of flexible plastic film 4. The sheet 2 is provided with aplurality of spaced perforations 6 and the corners are incised to enablefolding of the blank into a tray generally designated as 8. The cornersare preferably incised as illustrated, with parallel cuts 10 on opposedsides and inwardly sloping cuts 12 on the other sides.

Although the flexible films 4 may correspond substantially to theincised configuration of the sheet 2, they are of a somewhat larger sizeto enable sealing the two films about their periphery as at 13 toprovide a sealed envelope for the sheet 2. This is conveniently arectangular, unincised envelope as illustrated.

The cover for the tray 8, may be any transparent plastic material, butis preferably a heat-scalable material to enable ready closure of thepackage as illustrated in PEG. 1 by the numeral 14. Exemplary of thosethat may be employed are cellulose acetate, polyethylene, rubberhydrochloride, polyvinylidene chloride and other conventional wrappingfilms.

Although numerous transparent plastic materials may be employed, thecombination of a biaxially-oriented polystyrene semi-rigid sheet, andcellophane or cellulose acetate flexible films has been highlysatisfactory. However, other transparent plastic materials are alsosatisfactory, including polyethylene, rubber hydrochloride, polyvinyls,and various cellulose ethers and esters.

The semi-rigid sheet member should be of suflicient thickness to providethe required degree of rigidity but should not be so thick as to preventthe folding up of the sides to make the tray. Generally, a thickness ofabout 0.005 to 0.015 inch, and preferably about 0.0075 to 0.010 inch ispreferred. The films should be sufficiently thick to provide a highdegree of flexibility commensurate with strength for durability.

The tray is conveniently formed from the blank by folding the sides andthen adhering the cooperating film surfaces together either byheat-se-aling, or by application of adhesives or by use of a solvent torender the surfaces adherent.

The cover for the package may be any convenient plastic material. Aheat-sealing film is most easily employed and may be adhered to thesides of the tray or to itself on the bottom of the tray.

The transparent trays formed from the blanks of the present inventionenable storage of meats for prolonged periods of time. The plastic traysmay be printed or decorated in a suitable manner if desired withoutsubstantially interfering with the transparent nature of the package.

Having thus described the invention, I claim:

1. A package of meat including a folded transparent tray containerhaving a planar bottom wall and upstanding end and side walls, said traycontainer having a body member of a semi-rigid transparent plastic sheetencased in an envelope of transparent and relatively gas-permeableflexible plastic film providing layers of film on both sides of saidbody member, said plastic sheet having a multiplicity of perforationsspaced about the major portion thereof; and meat supported in saidcontainer, said package being characterized by substantial freedom fromdiscoloration of the meat for extended periods of time.

2. A package of meat consisting of a folded transparent tray having aplanar bottom wall and upstanding end and side walls, said tray having abody member of a semi-rigid transparent plastic sheet encased in anenvelop of transparent and relatively gas-permeable flexible plasticfilm providing layers of film on both sides of said body member, saidplastic sheet having a multiplicity of perforations spaced about themajor portion thereof; meat supported in said tray; and a cover oftransparent plastic film for said tray, said package being characterizedby substantial freedom from discoloration of the meat for extendedperiods of time.

3. In the method of packaging meat, the steps comprising encasing asemi-rigid transparent plastic sheet in an envelope of transparentflexible and relatively gas permeable plastic film, said semi-rigidplastic sheet having a multiplicity of perforations spaced about themajor portion thereof and being incised at its corners for formationinto a tray for receiving meat; folding said plastic sheet and film toprovide a tray having a bottom Wall and upstanding side and end Walls,said envelope providing plastic film upon both sides of said plasticsheet to provide pockets of air in said tray at the perforations;placing meat into said try; and providing a cover of transparent plasticfilm over said meat and tray to enclose said meat and provide a packagecharacterized by substantial freedom from discoloration of the meat forextended periods of time.

4. A blank for a transparent meat packaging tray comprising a planarsemi-rigid transparent plastic sheet and an envelope of transparentflexible and relatively gaspermeable plastic film enca'sing saidsemi-rigid plastic sheet, said semi-rigid plastic sheet having amultiplicity of perforations spaced about the major portion thereof andbeing incised at its corners for formation into a tray for receivingmeat, and said envelope providing plastic film upon both sides of saidplastic sheet to provide pockets of air therein at the perforations.

References Cited in the file of this patent UNITED STATES PATENTS1,234,730 Chapman July 31, 1917 1,482,727 Borchers Feb. 5, 19242,485,028 Bauernfrennd Oct. 18, 1949 2,717,731 Nerenberg Sept. 13, 19552,859,122 Maturi et al Nov. 4, 1958 2,870,954 Kulesza Jan. 27, 19592,918,379 Laurie Dec. 22, 1959

3. IN THE METHOD OF PACKAGING MEAT, THE STEPS COMPRISING ENCASING ASEMI-RIGID TRANSPARENT PLASTIC SHEET IN AN ENVELOPE OF TRANSPARENTFLEXIBLE AND RELATIVELY GASPERMEABLE PLASTIC FILM, SAID SEMI-RIGIDPLASTIC SHEET HAVING A MULTIPLICITY OF PERFORATIONS SPACED ABOUT THEMAJOR PORTION THEREOF AND BEING INCISED AT ITS CORNERS FOR FORMATIONINTO A TRAY FOR RECEIVING MEAT; FOLDING SAID PLASTIC SHEET AND FILM TOPROVIDE A TRAY HAVING A BOTTOM WALL AND UPSTANDING SIDE AND END WALLS,SAID ENVELOPE PROVIDING PLASTIC POCKETS OF AIR IN SAID TRAY AT THEPERFORASHEET TO PROVIDE POCKETS OF AIR IN SAID TRAY AT THE PERFORATIONS;PLACING MEAT INTO SAID TRY; AND PROVIDING A COVER OF TRANSPARENT PLASTICFILM OVER SAID MEAT AND TRAY TO ENCLOSE SAID MEAT AND PROVIDE A PACKAGECHARACTERIZED BY SUBSTANTIAL FREEDOM FROM DISCOLORATION OF THE MEAT FOREXTENDED PERIODS OF TIME.